This book describes an innovative approach to the interaction between humans and a smart environment; an attempt to get a smart home to understand intuitive, multi-modal, human-centred communication. State of the art smart homes, like other "smart" technology, tend to demand that the human user must adapt herself to the needs of the system. The hunt for a truly user-centred, truly intuitive system has long proven to be beyond the grasp of current technology. When humans speak with one another, we are multimodal. Our speech is supplemented with gestures, which serve as a parallel stream of information, reinforcing the meaning of our words. Drawing on well-established protocols in engineering and psychology, and with no small amount of inspiration from a particular nonsense poem, we have successfully concluded that hunt. This book describes the efforts, undertaken over several years, to design, implement, and test a model of interaction that allows untrained individuals to intuitively control a complex series of networked and embedded systems. The theoretical concepts are supported by a series of experimental studies, showing the advantages of the novel approach, and pointing towards future work that would facilitate the deployment of this concept in the real world.